Isothermal air compressor



c. w. svTANcLlFr-'E ISOTHERHAL AIR COMPRESSOR Filed Auz. 24. 1923 Dec. 22, 1925- Patented Dec. 22, 1925.

UNITED STATES.`

i 1,566,442 PATENT osrics- CECIL W. STANCLIFFR'OF NRW YORK, N. Y., ASSIGNOR To STANCLIFRR ENGINEERING CORPORATION, o1? NEW YORK, N. Y., A CORPORATION oF NEW YORK'.

IsotLrInRivrALl AIR COMPRESSOR.

Appncaunv filed August 24, 192s. seriaiNo. 659,074.

duce a machine adapted to compressair and 'samev other gases to whatever pressure may be desired, and at the same time Vto abstract the heat of compression from the air as fast, or nearly as fast, as developed, to the end that the temperature of the compressed air will be substantially as low as thatk of the air before compression, or at least not greatly higher, and substantially the full benefit of the work done in compress-ing the air will be retained and will not be subject to dissipation by loss of pressure through` subsequent cooling ofthe air. Y

In air compressors as-heretoforeused, 1t has been the custom to cool the compression cylinders by means of water, in order both to prevent too high aftemperature-being def veloped and to cool the air before compression; and in the practice of plural stage compression, it has been customaryv to. cool theA air additionally between the successive stages. Such cooling, however, does not secure isothermal compression or any 'result nearly approximating the maintenance of' uniform temperature, nor-prevent the temperature of the air at the end of the com-` pression mounting to a very high degree.

TheY particular purpose and accomplishment of this invention areto bring the cooling medium into such close and intimate Ythermal contact with the air being compressed and to'divide the .air in course of compression. into such smallfilms inj'such contact with cooled'enclosingwalls, that no substantial riseof temperature, duek to compression, can take place in the air and the pressure maybe raisedto any desired degree ina single stage of compression."v i

In the Vfollowing specification; I. Yhave de yscribed one of the forms of compressorembodying my invention by which? the desired results areobtained,andfin the accompanyingfdrawing I have .illustrateclth 'sor so described. l Memer-isser f e compres- Y compressor' referred to.

Air Compressors, of which the following is Figure 1 is yprincipally. aV longitudinalfsiection and partly a side ,elevation of the air Figure 2 is partly a cross sectionV and partly an end elevation as seen from the left ofFigure 1 of saidcompressor.

l Figure 3 is ay fragmentary sectional view showing one of the compressionnplungersl at theend of its compressing stroke.

' Likevreference characters kdesignate the parts wherever they occurin all `the figures. Y 5g In the drawings a representsa heat interchanger comprising; a substantially solid.

block of heat-conducting material having` a number of rows ofpassages b extending in parallel in one. direction, and a secondv `set rof passages o extending parallellto o ne another in a different direction and arranged in rows between" the rows of passages b. Such a heat interchanger is. disclosedl in myV prior application filed August 7 1922,- Serial N o. 580,073, andiit may be constructed as therein set forth.

Secured to one end of the unitfdis al chamber, preferably acylinder d, the axis `'of which is parallelwiththe axes of the kpassages o; and secured to the opposite end of the unit is a fitting e which encloses a Vchamber f in communication with the passages o. rThis fitting has an inlet valve g lthroughwhich airmayfbe drawn into the chamber, passages vand cylinder, and it has `also an outlet valve t throughl which the 'compressedfair may be expelled.' These valves are represented as vbeing self-closing against rthe" flow ofair in the opposite direction to that in which the air isdesigned to flow. 1 1 l j- ,Over the intermediate faces.l of fthe unit a, through which the passages open, are

vmounted and secured fittings i and j having connections to receive andv carryv away'k reV spectively a cooling fluid, such as water, or

any other fiuid KVwhich normally has', vor to which maybe given, a temperature low enoughfor the purpose4 in view.

piston 7c lworks in the cylinder 0l and is driven yby la piston rod `Z by any. suitable means. Although the showing of thepistonand its relation toy the cylinder; diagrammatic kin nature for ytheYprn-pose of illustration, it is `to be lunderstood that this piston ywill I)be properly made` and adequately packed to prevent appreciable leakage ot the air when compressed to the required pressure.

Plungers p are connected to the piston la and are @anal in number@ the passages C, each plunger being alined With one of the passages and adapted to move back and forth therein. These plungers do not fit the passages but are preferably enough smaller to permit tree tloiv ot air into the passages from the cylinder space While the compression stroke yis in progress. Also the plungers are tapered with the large end of the plunger next to the piston. 1n other Words, the arrangement ot the plungers is such that the clearance bet-Ween them and the Walls of the passages is at the minimum when the compression stroke ends.

1t will -be lreadily apparent that during the intake stroke oic the piston air is drawn through the passages c into the cylinder d and is more or less cooled by contact with the ivalls ot the passages, these Walls being maintained ata Ilow temperature by the cooling iliuid which passes through the passages Z2 and keeps the entire block a. at a low`temperature. 'During the compression stroke the volume of airY in the cylinder is forced through the passages c, and as the total capacity oit all the passages is much lessthan that ot the cylinder, the flow ot air through them takes place at a high velocity, which is conducive to the most cient i'loW of heat from the air being com pressed into the cooling medium. At all times, even when the piston is in its most remote position from the heat interchanger unit, the plungers project somewhat into the passages and leave open only the annular spaces between their surfaces and the Walls ot the passages for flow or" air.l Thus all the 'air Which passes through the cylinder is brought into ja close approach to a cylindrical film in Contact with the cool Walls of ther passages, and the flow velocity is made very high,`because of the small area of these annular spaces,

As theA compression pressure increases, due to progress' of the piston, the plungers are farther advanced into the passages, narrowing still further, on account of their tapered 4formation, the annular entrances to the passages and still further lling the central parts of the passages, leaving less opportunity for air to pass out of direct contact With the surrounding Walls.

Thus from the first, the airisbrought into intimate contact With the cooled Walls of the compression spaces and caused to flow at high velocit-y in contact With such Walls, and as the pressure becomes greater and the conditions occur Which tend to, raise the temperature of the air, the velocity of the air being compressed is increased and the intimacy of ,its contact with the enclosing Walls is still further enhanced. At the same time the large number of passages provi-ded tor the cooling medium, the close proximity ot these passages to the air compression passages, and the presence ot a solid mass ot material which is a good conductor or' heat, around and bet-Ween all ot the passages, enables the heat developed by compression of the air to be rapidly absorbed and carried avvay.

The chamber f into Which the compresser air is delivered may be ot as small volume as desired, to the minimum limit ot a space which is sufficient to conduct air from the inlet valve to the passages, and to conduct compressed air trom the passages to the outlet valve Without causing excessive vtricthyn. it is to be noted also that one Wall ot this chamber is thet surface ot the heat nterrhanger unit, which is maintained at lovv temperature, and the outer Wall of the chamber may also be provided -With a jacket containing a cooling medium, it' desired. 1 ain, tlieretore, able to accomplish the result ot' compressing air to any desired pressure and oi dissipating the heat of compression substantially as tast as such heat is generated, and ot delivering` air compressed to any pressure desired at a temperature substantially the same as its initial temperature, or even at a lovver temperature, in case a refrigerated cooling medium (that is, any medium of which the temperature is enough lower than that of the air tor the purpose mentioned)A is used. rlhe eiiiciency ot the apparat-us and its mechanical simplicity e able me to obtain very great economy .in air compression.

In this description I have used the term air compressor and terms of similar import in an illustrative and not a limiting sense. The machine or apparatus may be applied tor compressing any gases to any desired pressurc,"or :tor liquetying air and other gases. 1 intend to claim and protect the novel characteristics ot the apparatus in all. uses and for all purposes to which it may be put, and the descriptive terms herein used are to be construed accordingly.

What I claim and desire to secure by Letters Patent is:

1. An apparatus for the purposes set iorth comprising a heat interchanger unit constructed as a block o1'l substantially solid heatconducting material with a set of passages extending in one direction and a separate set ot passages extending in a different direction and arranged intermediate of the passages ot the first-named set, a chamber enclosing a gas-receiving space connected to one end of said unit in communication with one set of passages therein, a iitting at the opposite end of the unit having provisions for conducting gas to and away from said passages, means for conducting a cooling medium through the passages of the secondnamed set, and a piston working in said chamber toward and away from the unit.

AL2. An apparatus Vfor the purposes set forth comprising a'heat'interchanger unit constructed as a blockfof substantially solid heat-conducting material with a set of passages extending in one direction anda separate set of passages extending in a different direction and arranged intermediate of the passages of the first-named set, a cylinder enclosing a gas-receiving space connected to one end of said unit in communication with one set of passages therein, a fitting at the opposite end of the unit having provi-k sions for conducting gasto and away from said passages, means for conducting a cooling medium through the passages of the second-named set7 a piston Working in said cylinder toward and awayk from the unit, and plungers secured to said piston and projecting toward and into the first-named'pas-y sages, said plungers being of' lesstransverse dimensions than the passages and being adapted toreciprocate therein. y

8. An isothermal air compressor comprising a heat interchanging unit constructed substantially as a solidblock having a set of passages extending in one direction Vand a set of passages extending in the transverse direction, the passages of one set being interposed between passages of another set, and means for compressing air arranged to deliver the air so compressed into the passages of one set, whereby the. compressed air is cooled by ra cooling vmedium` flowing through the passages of the other set.

4. An isothermal air compressor comprising a yheat interchanging unit constructed substantially as a solid block having a set of passages extending in one direction and a set of'passages extending in the transverse direction, the passages of one set being interposed between passages of another set, and means for compressing air arranged to deliverV the air so compressed into the passages of one set, whereby the compressed air is cooled by a cooling medium flowing through the passagesv of the other set, combined with core pieces occupying centrally the passages of the first set and arranged to leave annular spaces between their lateral surfaces and the surrounding walls of such passages, whereby the air forced into these passages is caused lto flow with substantial velocity in the form of films close tosaid walls. 1

In testimony whereof I have aflixed my signature.

cEciL yw.y sTANoLIFFE.' 

